Hi, all I think I found a bug in ext4/extents.c, "ext4_ext_put_in_cache" uses "__u32" to receive physical block number. "ext4_ext_put_in_cache" is used in "ext4_ext_get_blocks", it sets ext4 inode's extent cache according most recently tree lookup (higher 16 bits of saved physical block number are always zero). when serving a mapping request, "ext4_ext_get_blocks" first check whether the logical block is in inode's extent cache. if the logical block is in the cache and the cached region isn't a gap, "ext4_ext_get_blocks" gets physical block number by using cached region's physical block number and offset in the cached region. as described above, "ext4_ext_get_blocks" may return wrong result when there are physical block numbers bigger than 0xffffffff. Regards YZ - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html